WHY it matters: Position size, targets and expectancy are ALL derived from the stop distance. If you don't know where you're wrong, you can't size the trade. Everything downstream flows from R.
WHAT: e.g. "always risk 2% below entry."
HOW (derive the stop price): For a long entry E and percent p:
Stop=E(1−p)
WHY it feels right: simple, consistent, no judgement.
WHY it's flawed: a 2% stop is huge on a sleepy utility and nothing on a volatile small-cap. It ignores how much the stock breathes → you get stopped by random noise.
ATR = average of TR over n bars (usually n=14):
ATRn=n1∑i=1nTRi
WHY derive it this way: ATR is the stock's typical one-bar move. Placing the stop at k times that means "only exit if the move is abnormally large against me" — you filter out normal noise automatically.
WHY it's the "smartest": the market itself defines the wrong-point. If you bought a bounce off a swing low at $100, a break below $100 means the bounce failed → your reason to be long is gone. So stop goes at, say, $99.7 (a small buffer below).
HOW: find the structural level → add a small buffer (often a fraction of ATR) so you sit outside the exact tick everyone watches → that's your stop.
To pre-define and cap your loss (one unit of risk R) at the price where your trade idea is proven wrong.
Formula for True Range?
TR=max(H−L,∣H−Cprev∣,∣L−Cprev∣).
Why does TR take the max of three values instead of just H−L?
To account for overnight gaps, so movement is never underestimated.
How is ATR built from TR?
ATR is the average (usually 14-period) of the True Range values.
ATR-based long stop formula?
Stop=E−k⋅ATR, with k typically 1.5–3.
Fixed percent long stop formula?
Stop=E(1−p).
Where does a structure stop go?
Just beyond (with a small buffer) a chart level like a swing low/high or support that would invalidate the thesis.
Why is a fixed % stop weak across different stocks?
It ignores volatility — same distance is too tight for volatile stocks and too wide for calm ones.
If risk is $500 and risk-per-share is $4, how many shares?
500/4=125 shares.
What should you shrink to reduce dollar risk instead of tightening the stop?
Position size (shares), keeping the stop at a logical distance.
Effect of increasing multiplier k?
Wider stop → fewer whipsaws but larger loss per trade (and smaller size).
Recall Explain it to a 12-year-old (Feynman)
Imagine you bet a friend that it'll rain tomorrow. A stop-loss is you saying "if the sun is out by noon, I lose and I quit — no arguing." A fixed stop is quitting after a set number of hours no matter what. An ATR stop is quitting only if it's way sunnier than a normal day, because a little sunshine is normal and doesn't mean you're wrong. A structure stop is quitting when something clearly proves you wrong — like a full rainbow of sunshine. The ATR and structure stops are smarter because they wait for a real sign you're wrong instead of a random cloud.
Dekho, stop-loss ka sirf ek kaam hai: pehle se decide karna ki agar trade galat hui to kitna paisa lose karna hai. Yeh tumhara "risk unit" R hai, aur position size, target, risk-reward — sab isi se nikalte hain. Bina stop ke tum size hi decide nahi kar sakte.
Teen tareeke hain. Fixed stop ekdum simple hai — bas 2% ya fixed dollar neeche laga do. Problem yeh hai ki har stock ka nature alag hota hai; ek calm stock ke liye 2% bahut zyada hai, ek volatile stock ke liye bahut kam. ATR stop isko smart banata hai: ATR matlab stock normally ek din me kitna move karta hai. Stop lagao entry se k×ATR door (usually k=2), taaki normal noise se tum bahar na nikal jao, sirf abnormal move par exit ho.
Structure stop sabse logical hai. Yahan market khud batata hai ki tum kab galat ho — jaise agar tumne swing low par bounce khela hai aur wo low toot gaya, to trade ka reason khatam. Bas us level se thoda buffer neeche stop rakho (kyunki sab log exact level par stop lagate hain aur wahin stop-hunt hota hai).
Sabse bada gyaan: risk ko position size se control karo, stop ko chhota karke nahi. Agar stop tight kar doge stock ke normal move se bhi kam, to har random jhatka tumhe nikaal dega — sahi trade me bhi loss. Isliye stop logical rakho, aur shares kam-zyada karke dollar risk fix rakho.
